JPH0654233B2 - Underground drilling hole accuracy confirmation device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for confirming the accuracy of an underground excavation hole, and more particularly to a device for confirming the accuracy of a groove-like underground excavation hole that is excavated while filling muddy water.

<< Conventional Technology and Problems >> As is well known, there is an underground continuous wall method as a construction method for retaining walls or water-stop walls provided when constructing an underground structure.

In this method, excavation is performed while the excavation slot is filled with mud water for the purpose of preventing the collapse of the excavation slot and ensuring the stability of the work. When the excavation of the ditch is completed, a rebar cage will be installed inside the ditch to place concrete without replacing mud water. Confirmation is done.

This confirmation is extremely important for ensuring the reliability of the construction, and it is usually measured whether or not the wall of the excavation groove collapses, or whether the groove width and depth are as designed. .

As a device for confirming the state of such an excavation groove hole, conventionally, there has been provided one that projects ultrasonic waves on the wall surface of the groove hole.

However, the ultrasonic confirmation device has the following problems.

That is, in the recent underground continuous wall construction method, the depth gradually increases, and for example, an underground continuous wall extending to hundreds of tens of meters has also appeared.

Since a large continuous earth pressure is applied to the underground continuous wall constructed at such a large depth, the muddy water filled in the excavation ditch may collapse unless the mud is effectively prevented. Grows larger.

It is effective to increase the concentration and viscosity of mud in order to prevent the loss of mud, and for example, those having a specific gravity of 1.2 or more are generally used.

In this case, according to the experiments by the present inventors, it becomes extremely difficult to confirm the accuracy of the excavation groove hole by the above-mentioned ultrasonic waves.

This is probably because ultrasonic waves are greatly attenuated in high-concentration and high-viscosity mud water and a clear reflected wave cannot be obtained, and the effect of bubbles contained in the mud water due to viscosity.

The present invention has been made in view of the above problems, and an object thereof is to provide an apparatus capable of confirming the accuracy of an excavation groove even when mud having a high concentration and a high viscosity is used. To provide.

<< Means for Solving the Problems >> In order to achieve the above object, the present invention confirms the accuracy of the groove hole suspended in the groove hole excavated while filling the muddy water having a specific gravity of 1.2 or more. an apparatus for in a depth gauge for suspended supporting the apparatus body, the device several hundred MH Z continuous or intermittent micro _to several GH _Z between the both side walls of the attached groove hole on the outside of the body A pair of antenna units for transmitting and receiving waves, a processing unit installed on the ground for controlling the antenna unit and performing processing / display based on the time delay of transmission / reception signals, and in the slot installed in the main body of the unit. And a means for measuring the posture of the.

In accuracy check device «work for» above configuration hundreds MH for observing the wall surface of the Z _~ number GH _Z of continuous or intermittent excavation hole by transmitting and receiving microwaves, a high concentration into the groove hole, high viscosity Even if it is filled with muddy water, the attenuation of microwaves is small, the directivity is good, and the wall surface can be clearly seen.

<< Examples >> Hereinafter, preferred examples of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 and FIG. 2 show the installed state of the accuracy confirmation device for an underground excavation hole according to the present invention, which is suspended in a ditch hole 12 excavated while being filled with muddy water 10. .

The accuracy confirmation device shown in the figure includes a winder 14 installed in the width direction of the slot 12, and a cylindrical device body 18 in which an electric cord 16 is wound around the winder 14 and suspended. A pair of antenna units 20 attached to the outside of the device body 18,
20, a processing unit 22 connected to the electric cord 16 for controlling the antenna unit 20 and for processing or displaying these transmission / reception signals, a processing unit 22 provided on the ground, and an apparatus main body 1
8 and a weight 24 that controls the posture in the slot 12.

The winder 14 also serves as a depth gauge for measuring the vertical distance in the slot 12 of the antenna unit 20 of the device body 18, and the rotation of the rotary shaft of the rotary encoder is converted into a linear distance. A sensor is installed, and the output of this sensor is also input to the processing device 22.

The antenna part 20 is located at a position facing the outside of the cylindrical device body 18, and is located on both side walls 12a and 12b of the slot 12.
Are suspended so that their surfaces face each other.

As shown in the plan view of FIG. 2, each antenna unit 20 is a substantially disk-shaped member, and has a transmitting antenna 20a and a receiving antenna 20b that are provided at a predetermined interval, Each of the antennas 20a and 20b is composed of a metal flat plate having substantially the same shape, and has a shape in which a pair of triangles are connected at apexes. It is housed inside.

The antenna unit 20 includes a microwave M hundreds MH _Z ~ number GH _Z sent through the electrical cord 16 from the processing device 22, each side wall 12a from the transmitting antenna 20a, 1
2b toward the side wall 12a continuously or intermittently.
, 12b, the microwave M reflected by each receiving antenna 2
Receive at 0b. Here, several hundred of using a microwave M of MH Z _~ number GH _Z, with the permeability of what directivity is improved deteriorated (attenuated) whereas the wavelength is shortened, is a transparent wavelength becomes longer This is for improving both the transparency and the directivity because the directivity is deteriorated though it is improved.

The processing device 22 includes a microwave M for each antenna unit 20.
Or calculate the distance between each antenna unit 20 and the side walls 12a and 12b based on the time delay of the microwave M between the transmitting and receiving antennas 20a and 20b, and based on the calculation result, the vertical distance measured by the depth gauge. Is displayed as a function of, for example, a microcomputer is used.

The weight 24 is attached to the lower end of the device body 18,
The posture of the main body 18 is in the vertical state, and the respective antenna parts 20 are oriented substantially toward the side walls 12a and 12b. However, even if the inclinometer measures the posture of the main body 18 in the vertical or horizontal direction, Good.

The checking device having the above configuration measures and displays the depth and the groove width by projecting and reflecting the microwave M from the upper end to the lower end of the groove 12 while gradually loosening the electric cord 16 of the winder 14.

The confirmation of the slot 12 by the microwave M is performed in the slot 12 by, for example, a highly concentrated and highly viscous muddy water 10 having a specific gravity of 1.2 or more.
Even if it is full, it can be clearly observed because the attenuation is extremely small and the directivity is good.

In the above embodiment, the antenna part 20 is provided on the side wall 12a,
An example is shown in which a pair is provided so as to face 12b.
Four antenna units 20 are attached so that the device body 18 is divided at approximately 90 degrees, and the horizontal position in the slot 12 of the device body 18 can be simultaneously measured by projecting and reflecting the microwave M. Good.

<< Effects of the Invention >> As described in detail above with reference to the embodiments, according to the accuracy confirmation device for an underground excavation hole according to the present invention, permeability and directivity can be obtained even for high-concentration, high-viscosity mud water. since use of continuous or intermittent microwave hundreds MH Z _~ number GH _Z which can be compatible, clear observation borehole, excellent effects such as can be confirmed obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view of an installation state of the device of the present invention, and FIG. 2 is a plan view of an antenna section of the device. 10 ... Muddy water, 12 ... Groove 14 ... Winder, 16 ... Electrical cord 18 ... Device body, 20 ... Antenna part 22 ... Processor

Claims (1)

[Claims] 1. A device for suspending and supporting a device body, which is a device for suspending and supporting a device body, the device being suspended in a ditch hole excavated while filling muddy water having a specific gravity of 1.2 or more. It is attached to the outside of the main body of the apparatus and is several hundreds of MH between both side walls of the slot.
_Z to several GH _Z , a pair of antenna units for transmitting and receiving continuous or intermittent microwaves, and a processing unit provided on the ground for controlling the antenna units and performing processing / display based on the time delay of transmission / reception signals, An apparatus for confirming accuracy of an underground excavation hole, which is mounted on the apparatus main body, and is provided with means for measuring a posture in the slot hole.